Trends and seasonal variation in the incidence and prevalence of irritable bowel syndrome in Korea: a multicenter OMOP CDM study.

Background: Irritable bowel syndrome (IBS) is a prevalent functional gastrointestinal disorder. Despite revisions of diagnostic criteria, studies applying the Rome IV criteria in Korea are limited. Environmental factors such as climate and season have been suggested to influence the epidemiology of IBS; however, their associations remain unexplored. Methods: We analyzed the prevalence and incidence of IBS in Korea from 2019 to 2023 using clinical data from eight nationwide hospitals converted to the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM). Stratified analyses were conducted by year, month, sex, and age. Seasonal variations were examined in relation to meteorological factors, including temperature and humidity. Results: Both the prevalence and incidence of IBS decreased during the study period. Females consistently showed higher rates than males, although the sex gap in incidence narrowed over time. The highest incidence rates were observed in individuals aged ≥65 years and those aged 15-19 years. Seasonal variation was evident, with peak incidence in autumn, followed by summer, significantly correlating with humidity and temperature. Conclusion: This multicenter study highlights sex- and age-specific differences in IBS epidemiology in Korea and demonstrates significant seasonal associations with meteorological factors. These findings underscore the need for large-scale, prospective surveys and public health strategies to address the IBS burden.